I was grinding money last night and I wondered, how much are the most expensive vehicles worth in Robux? So I did this(Note for XP value conversion I am using the most expensive xp pack. The value will be different if we use the cheaper xp pack):
Value of Nighthawk in Robux: 12,000R$
Work(For you math nerds): Value of cash=$500 per robux, Nighthawk=$6,000,000
6,000,000/500=12,000; Thats enough robux to buy you some of the low price limiteds! Or 42 real life $! (Using Devex exchange rates which is $.0035/Robux)
Value of Hyperglider/Light Bike/Thunderbird: 10,000R$
Work: Value of cash=$500 per robux, Hyper/Light/Thunder: $5,000,000
5,000,000/500=10,000; That can also buy you some cheap limiteds. or $35 real life dollars.
Now this section is for the current season reward vehicles by converting exp values.
Myron(Lv. 100): 3,960R$
Work: 50,000 exp=400R$; 50,000/400=125; Exp required to reach Rank n (From 1)= 50n(n-1) so 50*100(100-1)=495,000; 495,000/125=3960. That can buy you some quality hats, or all the game passes this game has! Or $13.86 of real life money.
Mercedes(Lv. 50)=98 R$
Work: 50,000 exp=400R$; 50,000/400=125; Exp required to reach Rank n (From 1)= 50n(n-1) so 50*50(50-1)=122,500; 122,500/125=98 R$. That can barely let you buy a full set of clothes for your avatar, or get the cheapest game passes in Roblox, or $0.34 in real life money.
Now this section is converting the Exp vehicles to Cash vehicles(I'm only gonna do Myron cuz I'm lazy. You can use the work I show to figure out prices for the Mercedes).
Work:500 cash= 1R$, 125 exp=1R$, 500/125=4, 4 cash=1 exp, Myron=495,000 exp, 495,000*4=$1,980,000. Seems about right, the Myron definitely performs miles ahead of the below 1 million supercars, but high end ones like Overdrive or Nero will give it a run for it's money, literally.